I built a new vSphere 5.5 vCenter server and now our backup admin says the Unitrends appliance cannot authenticate with it to do backups.
I had her try username@domainname and domainname\username
The user account is an Administrator with vCenter
Unitrends backup appliance
Do you see this user account added under permissions tab of vCenter with administrator role ?
Try using the SSO admin account "firstname.lastname@example.org", but make sure that email@example.com is added to vCenter with administrator role privilege.
Is your Unitrends appliance up to date on the latest software version? If not, you may be affected by this incompatibility outlined in this Unitrends KB article: Unitrends KB :: Cannot backup VMs with unsupported devices on ESXi 5.5 host (HW compatible with ver .... If you look toward the bottom, a resolution document is attached.